A. Andy had a large collection of trading cards of famous soccer players. Many ofhis cards featured either Neymar (15%) or Mbappe (10%). However, Andy grewincreasing discontent with Neymar’s behavior (as a “diver”) and traded all of his Neymar cards for other cards. Since Neymar cards were still quite valuable despitehis antics, he managed to trade one Neymar card for 3 other cards (but none of themfeatured Mbappe). After the trade, what fraction of his cards feature Mbappe?

B. Peter went on a two-day trip to visit his grandma. On the first day, he spent twice as much money on food than on gasoline. On the second day, he spent three times as much money on food than on gasoline. He spent twice as much money on the first day then on the second day, and he had no other expense (Peter slept in a tent overnight).Given Peter spent a total of $76 on gasoline, how much, in dollars, did he spend on food during the two-day trip in dollars?

C. The Math Olympiad program opened for enrollment on September 1st, already with 40 students pre-registered, all of whom were 5th-graders who participated the year before. On each day starting from (and including) September 1st, through word of mouth, more students signed up. Each day, 3 fourth-graders and 1 fifth-grader signed up. At the end of which day did the ratio of 4th-graders to 5th-graders first exceed 2– to –3? Please give the answer as a single number which is the day of the monthwhen the condition is met (e.g. if it is September 25th, the answer is 25).

P.S. You don't have to solve every problem. If you finish only one, it would still be great!

D. There were 3 printers in the workroom. One was very slow, one was faster, and onewas very fast. They were nicknamed Sloth, Monkey, and Cheetah. Ms. Morrison needed to print a large number of pages, and she knew that if she could use two of the printers, she could finish the job in 45, 60, or 90 minutes, depending on which two printers were available.What if she could use all 3 at the same time? How many minutes would it take to finish printing?

Guest Jan 9, 2021